#include "stm32f10x.h"

int16_t Encoder_Count;
uint16_t TestCount;

// B相下降沿和A相低电平时，才判断为正转
// A相下降沿和B相低电平时，才判断为反转

void Encoder_Init(void) {
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
    // AFIO
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
    // ... EXTI, NVIC 两个外设的时钟默认打开

    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    // AFIO外部中断引脚选择配置
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource0);
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource1);

    // EXTI
    EXTI_InitTypeDef EXTI_InitStructure;
    EXTI_InitStructure.EXTI_Line = EXTI_Line0 | EXTI_Line1;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; // 下降沿触发
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);

    // NVIC
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); // 分组是芯片共用的，不同模块应该只执行一次

    NVIC_InitTypeDef NVIC_InitStructure;

    NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
}

int16_t Encoder_Get(void) {
    int16_t Temp = 0;
    Temp = Encoder_Count;
    Encoder_Count = 0;
    return Temp;
}

void EXTI0_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line0) == SET) {
        if (GPIO_ReadInputDataBit(GPIOB, GPIO_Pin_1) == Bit_RESET) {
            Encoder_Count--;
        }
        EXTI_ClearITPendingBit(EXTI_Line0);
    }
}

void EXTI1_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line1) == SET)
    {
        if (GPIO_ReadInputDataBit(GPIOB, GPIO_Pin_0) == Bit_RESET) {
            Encoder_Count++;
        }
        EXTI_ClearITPendingBit(EXTI_Line1);
    }
}
